Last night i had to repair a Rotel RB 830 typical amp with 100uf capacitor in the feedback chain ...there rod says : you may add a 100nf plastic capacitor if it pleases you but don't expect much to change ...

well Rotel in the specific amplifier uses a MKP capacitor bypassing a horrible quality 6.3V/100uf can anybody explain why ?

Then again similar practice goes to Luxman or Marantz equipment that selectively use type A capacitors in the signal path/compensation or type B in other applications .Obviously that is done to reduce the cost BUT also because it serves the sonic signature that the designer wanted to have .

So expect that they 've done the exact same choices with transistors to come up with the specific results or the opposite adjusted the circuit with proper compensation and miller and filtering to achieve the wanted sonic result ...

so transistors do sound different any way you slice it the point is how much of this is audible in an other wise same circuit of amplifier ....

sbrads sorry i don't get the meaning of the question can you please be more specific

kind regards
sakis

Sorry. What I meant was this....You have, through years of endeavour, decided that A is better than B which is better than C etc etc. These tests would have been done in a particular sequence, perhaps by chance, as I presume you had no pre-conceived ideas as to which may be best. Eventually you came up with your preferences. Did you then compare your top choice with earlier rejected lower order ones to re-confirm your decision, preferably after a period of time has elapsed so as to get that chance again of 'first impressions'?

since original 2SA1302 2SC 3281 are no longer really available though i have still about 100pcs closely matched pairs direct order from Toshiba dated 1996( which i am planing to use all for personal amusement )

and since i have produced a few P3A amplifiers which one was made for a friend some others for costumers and so on of course there i went with 1943-5200 in order to keep my fleet of originals i had the chance to verify my results once more

yet again i have produced other amplifiers that i have made similar tests with similar results but not extensive next to the P3A that i ma working with currently ...

For the record students in my back yard produced a P3A in a vero board for a school project and used carbon resistors ceramic capacitors 3055-2955 outputs at 24+24 rails Forget the power but it sounded and measure simply horrible...

Well, that's interesting.
Would you be so kind to provide measurements of 2 P3, one using humble 2N3055/2955 vs. an exact same one using "audiophile" transistors?
Please, one variable at a time, let's not change drivers/capacitors/resistors/PCB/PSU/etc. so as not to pollute the comparison.
I accept your subjective tests ("horrible"), but not being in the same listening room as you (I'd love to visit Greece again ), I'd settle for the second best, a nice set of numbers.
Thanks.

my version of P3A will make 40KHZ square wave on the scope flawless a variant with 2955-3055 will make no more than 16 before rounded up ( though this test was done 4 years ago and i have to make a lot of digging to find the measuring set of that long ago so i might be wrong )

For you pleasure though with in the next days i will upload a set with a couple of variants
All these have nothing to do with listening tests ,... that comes after measuring ...always

yeah useless even the SemiSouth SIC transistors are also waste...
why was that Transistor sounded so good and why does Nelson has to collaborate with Semiconductor companies to make a new Transistor which no one ever find difference at all..

why does chord uses its custom built output devices...

why does all this happen when one is getting everything off the shelf.. when you say its waste thread it does really reflects how how much one is behind the material science and great insult to the leads in the audio industry...

i have to make a lot of digging to find the measuring set of that long ago

Ok, thanks.
If you find them, fine.
If it complicates your life .... don't worry.
At least, instead of a word (horrible) which by itself means nothing, now you qualify by saying "one passes flawless 40KHz squarewaves, the other starts rounding 16KHz ones"
Well, yes, that's a difference, no doubt, but it usually means the amp reaches at least flat 30 or 40 KHz (sinewave) and often beyond that.
Not bad at all.
Qualifies for "horrible"? Mmmmm, who knows?
What I'm sure is that it will take for a lot of *flawless* equipment to notice it by itself.
Good luck

I disagree on the people claiming that this thread is pointless.
Active devices distorts a lot and impact the sound no less than a capacitor on the signal path and nowadays almost nobody negates that effect.

__________________"The total harmonic distortion is not a measure of the degree of distastefulness to the listener and it is recommended that its use should be discontinued." D. Masa, 1938